T cell receptors (TCRs)
A T cell receptor spans the membrane and projects variable binding regions into the extracellular space to bind processed antigens via MHC molecules on APCs.
Source
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:
"OpenStax College, Adaptive Immune Response. December 10, 2013."
http://cnx.org/content/m44821/latest/
OpenStax CNX
CC BY 3.0.